Free-Flow Driving over the New Columbia River Bridge
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Political leaders from Oregon and SW Washington agreed last week to build a 12-lane bridge over the Columbia River to replace the I-5 Interstate Bridge. The new facility will be financed in part through tolls, collected electronically at travel speeds via tolltags.
A new Mobility Council will be formed to oversee operations. The Council is likely to vary the toll rates by time of day, direction of travel, and day of the week, in order to ensure free-flow traffic conditions at all times. We know from experience in California and elsewhere that variable toll rates dramatically improve travel speeds and also increase the vehicle throughput per lane, compared with unpriced lanes.
Since the new bridge will eliminate traffic congestion, there is no longer any rationale for the expensive light rail component of this project. Light rail would only increase peak hour passenger capacity of the bridge by about 15%, while adding more than $1.2 billion in construction cost. We could move 10 times more transit customers, at much higher speeds, by simply adding express bus service from Vancouver to Portland. The total capital cost of the new buses would be less than 1% of the cost of light rail.
A new bridge with congestion pricing is a good idea. Adding express bus service would make it a great idea.